Microanatomy

Question 1

Histology

Answer 1

Science concerned with the microscopic structure of cells, tissues, organs and their function.
a.k.a. microanatomy

Question 2

Tissue

Answer 2

Cellular and fibrous elements in which one particular type of cell or fiber usually predominates.

Organized to form the material basis of one of the functional systems of the body.

Question 3

Cell

Answer 3

The smallest unit of an organism which can carry out self-sustaining functions

Question 4

Tissue preparation

4 Steps

Answer 4

1. Stop biological activity and degradation
2. Tissues are decalcified, dehydrated, and perfused into an embedding medium (paraffin or resin)
3. Tissues are stained
4. Sliced into very thin sections

Question 5

Fixation

Answer 5

Cause linkage of macromolecules.
Increases effectiveness of staining.
Shrinkage is a frequent byproduct.
Some degree of distortion occurs to cells

Question 6

Staining

Answer 6

Facilitates microscopic observations dependent on the intrinsic characteristics of the cell.

Question 7

Acidic dyes

Answer 7

Carry a negative charge
React with ionic + cell structures:
Ionized amino groups or proteins

Question 8

Basic dyes

Answer 8

Carry a positive charge
React with anionic - cell structures:
Phosphate groups of nucleic acids, sulfate groups of glycosaminoglycans, and carboxyl groups of proteins

Question 9

Basophilic

Answer 9

Refers to cellular/extracellular elements

Include portions of chromatin, nucleoli, ergatosplams, and carbohydrate groups of cartilage matrix.

Question 10

Acidophilic

Answer 10

Eosinophilic
Include most cytoplasmic filaments, most intracellular structures, and most unspecialized cystoplasm, and most extracellular fibers (ionized amino groups).

Question 11

Ergastoplasm

Answer 11

Portion of cytoplasm that stains with basic dyes to phosphate groups of RNA

Question 12

H & E

Answer 12

Hematoxylin & Eosin
Hematoxlyin = behaves like basic dye
Eosin = an acid dye

Question 13

Light microscopy

Answer 13

LM
Examination of stained sections by transillumination
Use 3 types of lenses:

Question 14

Electron microscopy

Answer 14

EM
Small blocks of fresh tissue are rapidly fixed

A beam of electrons are sent through tissue, they can’t penetrate through glass, so specimen is mounted on metal grids.

Question 15

Plasma membrane

Answer 15

Plasmalemma
The selective barrier, acts as the “skin”.

Protects, communicates and has specific receptors for outer boundary of the cell.

Has a trilaminar appearance (ectoderm, mesoderm, endoderm) layers.

Question 16

Tight junctions

Answer 16

Protein molecules of adjacent cells fuse together like a zipper
Ex: GI Tract

Question 17

Desmosomes

Answer 17

Raised thickenings on cell walls.

Send keratin filaments to attach to desmosomes of adjacent cells

Question 18

Gap junctions

Answer 18

Hollow protein cylinders “connexons”
Has protonatious ring
Ex: Skin

Question 19

Protonatious ring

Answer 19

Creates a pore to allow certain molecules through based on size

Question 20

Cell-to-cell junctions

Answer 20

3 Types:
Tight junctions
Desmosomes
Gap junctions

Determine how cells are linked to each other and interact

Question 21

Glycocalyx

Answer 21

Like the fingerprint of a cell.

Immune cells read this to identify cells

Question 22

Plasma membrane structure

Answer 22

Has two layers of phospholipid molecules
Hydrophilic faces water
Water is outside and inside every cell - super important to send/recieve messages and transact nutrients
Hydrophobic faces inward on both sides of phospholipid layers

Question 23

Cytoplasm

Answer 23

Cytoplasmic matrix
Combo of cytosol and organelles.
More organelles = more function
*think jello mold with its contents

Question 24

Organelles

Answer 24

Operate within cytosol and inclusions are suspended within it.

Question 25

Mitochondria

Answer 25

Eosinophilia when present in great quantities. ATP occurs here. Very reliant on the presence of Type I muscle fibers (slow twitch).

Question 26

Ribosomes

Answer 26

Basophilic. Produced dark regions of cytoplasm Nissl bodies (via E.R. of neurons), or Basophilic bodies (most other cells).

Question 27

Rough endoplasmic reticulum

Answer 27

Basophilic structures High RNA presence A system of tubes within: Ribosomes externally Cysternae internally

Question 28

Microtrabecullae of the matrix

Answer 28

Cross sectional structural network of the cytoplasmic matrix

Question 29

Smooth endoplasmic reticulum

Answer 29

Eosinophilic cytoplasm if plentiful. A highly membranous structure.

Question 30

Cysternae

Answer 30

Fluid filled sites | Protein modification inside R.E.R.

Question 31

Oxidative phosphorylation

Answer 31

Mitochondria are efficient at ATP generation

Question 32

Golgi apparatus

Answer 32

Storage & protein synthesis

Question 33

Lysosomes

Answer 33

Membrane sacs of digestive enzymes for intracellular digestion. Degradation of worn out organelles. Function: Removes waste, garbage

Question 34

Cytoskeleton

Answer 34

Elements include: Microfilament Microtubules Microtrabeculae

Question 35

Microfilament

Answer 35

Act in cell structure, movement, contraction and division. Have network like appearance

Question 36

Microtubules

Answer 36

Act as conveyer belts inside cells

Question 37

Microtrabeculae

Answer 37

Helps suspend and organize components of cytoplasm and organelles

Question 38

Nucleus

Answer 38

Negatively charged Basophilic Intensity depends on concentration of DNA /RNA

Question 39

Nuclear membrane

Answer 39

Appears as two layered phospholipid barrier. | Has pores present for movement of RNA molecules out and protein molecules in.

Question 40

Chromatin & Activity

Answer 40

Thread like structures made of DNA and "histone proteins" High synthetic activity is a reflection of dispersed chromatin large nuclei Low synthetic activity is a clumping of chromatin and poorly visible nucleoli.

Question 41

Nucleoli

Answer 41

Darkly stained bodies with no membranes High synthetic activity is a reflection of rRNA synthesis.

Question 42

Muscle Tissue

Answer 42

Uniquely excitable Soft tissue that gives rise to muscles' ability to contract.

Question 43

Nervous Tissue

Answer 43

Uniquely excitable Makes up the CNS & PNS Function: integration and communication

Question 44

Epithelial Tissue

Answer 44

Very flexible in activity. The go-to for barrier membranes. Function: Line the outer surfaces of organs and blood vessels

Question 45

Connective Tissue

Answer 45

"Catch all" If not muscle, nervous, or epithelial then it's connective! Ex: blood, bone, cartilage, ligaments, tendons, etc... Very plastic in appearance and have many functions.